# Math Help - values

1. ## values

Find values of A, B, C AND R

x^3 - x^2 -x +12 = (x+2)(Ax^2 + Bx + C) + R

thanks

2. Originally Posted by gracey
Find values of A, B, C AND R

x^3 - x^2 -x +12 = (x+2)(Ax^2 + Bx + C) + R

thanks
$x^3-x^2-x+(12-r)=(x+2)(ax^2+bx+c)$

divide LHS by (x+2) you get:
$\frac{x^3-x^2-x+(12-r)}{(x+2)}$

= $x^2-3x+5$ and a simultaneous equation for r:
$5x+12+R=5x+10 \Rightarrow$R=2

So: A=1, B=-3, C=5 and R=2.